Adding upstream version 13.4.upstream/13.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 117 insertions, 0 deletions

diff --git a/src/backend/rewrite/rewriteSupport.c b/src/backend/rewrite/rewriteSupport.c
new file mode 100644
index 0000000..fc9a3b1
--- /dev/null
+++ b/src/backend/rewrite/rewriteSupport.c
@@ -0,0 +1,117 @@
+/*-------------------------------------------------------------------------
+ *
+ * rewriteSupport.c
+ *
+ *
+ * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  src/backend/rewrite/rewriteSupport.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/htup_details.h"
+#include "access/table.h"
+#include "catalog/indexing.h"
+#include "catalog/pg_rewrite.h"
+#include "rewrite/rewriteSupport.h"
+#include "utils/fmgroids.h"
+#include "utils/inval.h"
+#include "utils/lsyscache.h"
+#include "utils/rel.h"
+#include "utils/syscache.h"
+
+
+/*
+ * Is there a rule by the given name?
+ */
+bool
+IsDefinedRewriteRule(Oid owningRel, const char *ruleName)
+{
+	return SearchSysCacheExists2(RULERELNAME,
+								 ObjectIdGetDatum(owningRel),
+								 PointerGetDatum(ruleName));
+}
+
+
+/*
+ * SetRelationRuleStatus
+ *		Set the value of the relation's relhasrules field in pg_class.
+ *
+ * NOTE: caller must be holding an appropriate lock on the relation.
+ *
+ * NOTE: an important side-effect of this operation is that an SI invalidation
+ * message is sent out to all backends --- including me --- causing relcache
+ * entries to be flushed or updated with the new set of rules for the table.
+ * This must happen even if we find that no change is needed in the pg_class
+ * row.
+ */
+void
+SetRelationRuleStatus(Oid relationId, bool relHasRules)
+{
+	Relation	relationRelation;
+	HeapTuple	tuple;
+	Form_pg_class classForm;
+
+	/*
+	 * Find the tuple to update in pg_class, using syscache for the lookup.
+	 */
+	relationRelation = table_open(RelationRelationId, RowExclusiveLock);
+	tuple = SearchSysCacheCopy1(RELOID, ObjectIdGetDatum(relationId));
+	if (!HeapTupleIsValid(tuple))
+		elog(ERROR, "cache lookup failed for relation %u", relationId);
+	classForm = (Form_pg_class) GETSTRUCT(tuple);
+
+	if (classForm->relhasrules != relHasRules)
+	{
+		/* Do the update */
+		classForm->relhasrules = relHasRules;
+
+		CatalogTupleUpdate(relationRelation, &tuple->t_self, tuple);
+	}
+	else
+	{
+		/* no need to change tuple, but force relcache rebuild anyway */
+		CacheInvalidateRelcacheByTuple(tuple);
+	}
+
+	heap_freetuple(tuple);
+	table_close(relationRelation, RowExclusiveLock);
+}
+
+/*
+ * Find rule oid.
+ *
+ * If missing_ok is false, throw an error if rule name not found.  If
+ * true, just return InvalidOid.
+ */
+Oid
+get_rewrite_oid(Oid relid, const char *rulename, bool missing_ok)
+{
+	HeapTuple	tuple;
+	Form_pg_rewrite ruleform;
+	Oid			ruleoid;
+
+	/* Find the rule's pg_rewrite tuple, get its OID */
+	tuple = SearchSysCache2(RULERELNAME,
+							ObjectIdGetDatum(relid),
+							PointerGetDatum(rulename));
+	if (!HeapTupleIsValid(tuple))
+	{
+		if (missing_ok)
+			return InvalidOid;
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("rule \"%s\" for relation \"%s\" does not exist",
+						rulename, get_rel_name(relid))));
+	}
+	ruleform = (Form_pg_rewrite) GETSTRUCT(tuple);
+	Assert(relid == ruleform->ev_class);
+	ruleoid = ruleform->oid;
+	ReleaseSysCache(tuple);
+	return ruleoid;
+}